7. Incapacitation and Risk

Among Bentham’s mechanisms to prevent crimes (see Chapter 3) is removing ‘the physical power of offending … [so that] the individual can no more commit the offence’ (Bentham 1843, quoted in von Hirsch, Ashworth and Roberts 2009: 53). This is the subject of this chapter. It is to be noted that Bentham put this mechanism first in his list, and many people may reasonably feel that incapacitation (as we shall call this removing of ‘the physical power of offending’) has a certainty that other mechanisms lack. The efficacy of crime prevention achieved by locking someone up (the most familiar mode of incapacitation) does not depend on uncertain attempts to change the thinking of the individual or others and is accordingly not vulnerable to some of the critiques levelled in earlier chapters against deterrence (Chapter 5) or rehabilitation (Chapter 6). With this in mind, it is sometimes said that at least people cannot commit crimes while they are in prison. But one immediate qualification of this claim was raised in the Introduction.